Retroperitoneal sarcomas

Surgical management of giant retroperitoneal liposarcoma: Case report

Tumors originating from soft tissues are uncommon, among these tumors, liposarcomas are the most frequent. These tumors remain asymptomatic for a long time, and only revealing themselves when they reach an important size. In such cases, treatment is difficult, requiring extensive surgery procedures that can excise several adjacent structures, potentially completed by adjuvant radiotherapy. Despite successful treatment, the recurrence rate remains very high. We report the case of a giant liposarcoma requiring a monobloc extensive resection involving the removal of the tumor, left kidney, left adrenal gland, and a portion of the posterior abdominal wall.

Rapid and Precise Diagnosis of Retroperitoneal Liposarcoma with Deep-Learned Label-Free Molecular Microscopy

The retroperitoneal liposarcoma (RLPS) is a rare malignancy whose only curative therapy is surgical resection. However, well-differentiated liposarcomas (WDLPSs), one of its most common types, can hardly be distinguished from normal fat during operation without an effective margin assessment method, jeopardizing the prognosis severely with a high recurrence risk. Here, we combined dual label-free nonlinear optical modalities, stimulated Raman scattering (SRS) microscopy and second harmonic generation (SHG) microscopy, to image two predominant tissue biomolecules, lipids and collagen fibers, in 35 RLPSs and 34 normal fat samples collected from 35 patients. The produced dual-modal tissue images were used for RLPS diagnosis based on deep learning. Dramatically decreasing lipids and increasing collagen fibers during tumor progression were reflected. A ResNeXt101-based model achieved 94.7% overall accuracy and 0.987 mean area under the ROC curve (AUC) in differentiating among normal fat, WDLPSs, and dedifferentiated liposarcomas (DDLPSs). In particular, WDLPSs were detected with 94.1% precision and 84.6% sensitivity superior to existing methods. The ablation experiment showed that such performance was attributed to both SRS and SHG microscopies, which increased the sensitivity of recognizing WDLPS by 16.0 and 3.6%, respectively. Furthermore, we utilized this model on RLPS margins to identify the tumor infiltration. Our method holds great potential for accurate intraoperative liposarcoma detection.

Case Report: Successful R0 resection in locally advanced retroperitoneal sarcomas

We present a case series of three successfully resected tumors in our center at Al-Makassed Hospital in Jerusalem, Palestine, all of which primarily involved or invaded adjacent structures and needed a multidisciplinary approach to achieve R0 resection. Our first patient is a 42-year-old previously healthy female with intermittent attacks of dull aching abdominal pain. Her tumor was a leiomyosarcoma that involved major vessels and other adjacent vital structures. Ultimately, she needed major highly advanced surgery necessitating the need for vascular reconstruction of the IVC, as well as R0 resection. The surgery was performed by a multidisciplinary team of highly specialized surgeons in related fields. Our second case is a 75-year-old female patient with a well-differentiated liposarcoma invading the upper pole of the right kidney, necessitating a nephrectomy. Consequently, this case demanded the interdisciplinary involvement of nephrology. Our third patient is a 59-year-old male with dedifferentiated liposarcoma that involved the spleen, pancreas, and splenic flexure while engulfing the left kidney and ureter. Beyond the removal of the tumor, multiorgan resection was imperative to achieve microscopic margin-free resection. This extensive local spread needed broad collaboration from the medical team and other surgical subspecialties. All surgeries went well, and their outcomes were promising. All patients had an uneventful follow-up and, to date, no recurrence. Invasive retroperitoneal sarcomas of different histological types and clinical stages represent a technical challenge. Careful preoperative investigation and an experienced, dedicated multidisciplinary team of surgeons and non-surgeons from related fields, including vascular, urologic, and hepatobiliary surgeons, are usually needed for a safe and successful R0 resection despite extensive tumor involvement in light of difficulty achieving early diagnosis.

A giant liposarcoma originating from peripancreatic fat tissue with identification using 3D-CT angiography: a case report

BACKGROUND

Liposarcoma originating from peripancreatic fat tissue is extremely rare. This case report presents a surgical case of a giant liposarcoma originating from peripancreatic fat tissue with origin identification using 3-Dimensional Computed Tomography Angiography (3D-CTA).

CASE PRESENTATION

A 59-year-old female was referred to our hospital with a giant abdominal tumor. Computed tomography revealed a 34 cm tumor composed of fatty tissue, exerting pressure on the posterior aspect of the pancreas. Suspecting liposarcoma, we planned for surgery. At first, the tumor appeared to be intra-abdominal tumor, based on the identification of the tumor's feeding artery as a branch of the dorsal pancreatic artery using 3D-CTA, we concluded that the liposarcoma originated from the peripancreatic fat tissue and situated in the retroperitoneum. During surgery, we observed a well-capsulated, elastic, yellowish mass without infiltration into surrounding tissues. We carefully dissected the tumor from the greater omentum and transverse mesocolon while preserving the tumor capsule. We ligated the feeding artery at the border with the pancreatic parenchyma and successfully completed the excision of the tumor. The resected specimen weighted 2620 g and was pathologically diagnosed as a well-differentiated liposarcoma. There was no injury to the tumor's capsule, and the surgical margins were negative.

CONCLUSIONS

In this report, we present an extremely rare case of a liposarcoma originating in the peripancreatic fat tissue. The use of 3D-CTA was instrumental in identifying the primary site of this giant tumor, enabling us to guide the surgery and achieve complete resection successfully.

Resection of Retroperitoneal Extra-Adrenal Pheochromocytoma: A Case Report

Extra-adrenal pheochromocytomas are rare catecholamine-producing tumors that arise from chromaffin cells outside the adrenal glands. We report on the case of a 62-year-old male who initially presented with upper respiratory tract symptoms and was found to have a suprapubic pelvic mass and an asymptomatic right inguinal hernia. The diagnostic evaluation involved an abdominal ultrasound, a CT scan, followed by an MRI, which revealed a well-marginated large mass whose characteristics indicated a retroperitoneal sarcoma. Upon successful surgical resection, the mass was found to be encapsulated and no peripheral structure invasion was present; the right inguinal hernia was repaired, and a double J-stent was placed. Histopathological examination revealed extra-adrenal pheochromocytoma. This case report sheds light on diagnostic and therapeutic challenges when dealing with extra-adrenal pheochromocytomas and the importance of considering them as a differential diagnosis when presented with a case of retroperitoneal mass.

Cystic retroperitoneal dedifferentiated liposarcoma: A case report

Liposarcoma is the most common primary retroperitoneal sarcoma in adults. We report the case of an 86-year-old male who presented to the emergency department with frequent falls and unexplained weight loss that was found to have a cystic retroperitoneal dedifferentiated liposarcoma. Initial computed tomography revealed a large heterogeneous complex cystic hypoenhancing lesion in the left retroperitoneum. Subsequent magnetic resonance imaging demonstrates a multilocular cystic mass with microscopic lipid content, diffusion restriction, and enhancing nodular soft-tissue components. Histologic examination of the tissue sample following biopsy is consistent with cystic retroperitoneal dedifferentiated liposarcoma. Further management was not pursued due to the patient's advanced age and frailty.

Transarterial Embolization and Percutaneous Ablation of Primary and Metastatic Soft Tissue Tumors

Soft tissue tumors (STTs) include a range of benign and malignant tumors originating from soft tissues. Transarterial and percutaneous therapies are image-guided and minimally invasive approaches for managing primary and metastatic STTs. The objective of this review is to discuss transarterial and percutaneous therapies by examining the current literature, including indications, patient selection, safety, and effectiveness. Transarterial therapies (e.g., transarterial bland embolization and transarterial chemoembolization) involve the delivery of either embolic or chemotherapeutic particles using a catheter into arteries feeding the tumor, resulting in localized tumor destruction. Percutaneous therapies (e.g., radiofrequency ablation, cryoablation, irreversible electroporation, laser ablation, and magnetic resonance-guided high-intensity focused ultrasound) involve the delivery of either hot or cold temperatures, electrical current, laser, or ultrasound to specifically target tumor cells. Both therapies have been shown to be safe and effective for reducing morbidity and local control of STTs, specifically in patients who are surgically inoperable or who are unresponsive to conventional therapies. Accurate diagnosis, staging, and histological subtype identification are crucial for treatment selection. A multidisciplinary approach, a thorough understanding of tissue anatomy and surrounding structures, as well as individualized strategies based on assessment are essential for optimal patient care.

Sarcopenia and frailty as predictors of surgical morbidity and oncologic outcomes in retroperitoneal sarcoma

BACKGROUND

Retroperitoneal sarcomas (RPS) are rare tumors for which surgical resection is the principal treatment. There is no established model to predict perioperative risks for RPS. We evaluated the association between preoperative sarcopenia, frailty, and hypoalbuminemia with surgical and oncological outcomes.

METHODS

We performed a prospective cohort analysis of 65 RPS patients who underwent surgical resection. Sarcopenia was defined as Total Psoas Area Index ≤ 1st quintile by sex. Frailty was estimated using the modified frailty index (mFI). Logistic regression models were used to assess predictors of 30-day postoperative morbidity. The Kaplan-Meier method with log-rank test was utilized to assess factors associated with overall (OS) and recurrence-free survival (RFS).

RESULT

Sarcopenia was associated with worse OS with a median of 54 compared with 158 months (p = 0.04), but no differences in RFS (p > 0.05). Hypoalbuminemia was associated with worse OS with a median of 72 compared with 158 months (p < 0.01). MFI scores were not associated with OS or RFS (p > 0.05). Sarcopenia, mFI, and hypoalbuminemia were not associated with postoperative morbidity (p > 0.05).

CONCLUSION

This study suggests that sarcopenia may be utilized as a measure of overall fitness, rather than a cancer-specific risk, and the mFI is a poor predictive measure of outcomes in RPS.

Analysis of potential risk factors in the survival of patients with primary retroperitoneal liposarcoma

INTRODUCTION

The present work is an observational study of a series of variables regarding overall survival and disease-free survival in patients diagnosed with primary liposarcoma.

METHODS

The study is prospective with retrolective data collection that includes all patients with primary liposarcoma referred to Hospital Son Espases University Hospital, Palma de Mallorca, Spain from January 1990 to December 2019.

RESULTS

The study includes 50 patients and the compartment surgery was performed in 18 patients (36%) of cases. The mean overall survival of the sample was 15.57 years (95% CI: 12.02-19.12) and the mean disease-free survival was 6.70 years (95% CI: 4.50-8.86).

CONCLUSION

Compartment surgery has not shown benefits in terms of overall survival and disease-free survival. The ASA classification (≥3) predicts a poor prognosis in both overall survival and disease-free survival. Resection with free margins, described on the pathological results and defined in this work as R0, show better disease-free survival.

Carbon-ion radiotherapy for urological cancers

Carbon-ions are charged particles with a high linear energy transfer, and therefore, they make a better dose distribution with greater biological effects on the tumors compared with photons and protons. Since prostate cancer, renal cell carcinoma, and retroperitoneal sarcomas such as liposarcoma and leiomyosarcoma are known to be radioresistant tumors, carbon-ion radiotherapy, which provides the advantageous radiobiological properties such as an increasing relative biological effectiveness toward the Bragg peak, a reduced oxygen enhancement ratio, and a reduced dependence on fractionation and cell-cycle stage, has been tested for these urological tumors at the National Institute for Radiological Sciences since 1994. To promote carbon-ion radiotherapy as a standard cancer therapy, the Japan Carbon-ion Radiation Oncology Study Group was established in 2015 to create a registry of all treated patients and conduct multi-institutional prospective studies in cooperation with all the Japanese institutes. Based on accumulating evidence of the efficacy and feasibility of carbon-ion therapy for prostate cancer and retroperitoneal sarcoma, it is now covered by the Japanese health insurance system. On the other hand, carbon-ion radiotherapy for renal cell cancer is not still covered by the insurance system, although the two previous studies showed the efficacy. In this review, we introduce the characteristics, clinical outcomes, and perspectives of carbon-ion radiotherapy and our efforts to disseminate the use of this new technology worldwide.

Giant retroperitoneal well-differentiated liposarcoma presenting in emergency with intestinal occlusion: Case report and review of the literature

INTRODUCTION AND IMPORTANCE

Liposarcoma (LPS) represents the most common type of retroperitoneal sarcoma (RPS) and can be classified into four subtypes. Preoperative diagnosis of retroperitoneal liposarcoma (RLPS) is a challenge because of its late and nonspecific clinical presentation. Imaging may be helpful for determining the correct diagnosis. Surgery represents a potentially curative treatment of RLPS.

CASE PRESENTATION

A 55-year-old Caucasian female presented to the Emergency Department with a two-day history of abdominal pain, abdominal distension, inability to pass gas or stool, nausea, vomiting and lipothymia. Abdominal examination revealed abdominal distention, abdominal pain without obvious muscle guarding and a giant non-tender mass. Laboratory tests reported neutrophilic leukocytosis and anemia. Abdominal contrast-enhanced computed tomography (CECT) showed a heterogeneous and hypodense giant retroperitoneal mass compressing and displacing the surrounding organs and vessels. The patient underwent excision of a giant retroperitoneal mass. The postoperative course of the patient was uneventful.

CLINICAL DISCUSSION

RLPS is a malignant neoplasm that can slowly grow to enormous size with possible involvement of adjacent organs and vessels; it may recur locally and has a minimal capacity to metastasize. Preoperative diagnosis and staging of RLPS are important to establish appropriate management and prognosis. Surgery represents the gold standard for non-metastatic RLPS treatment.

CONCLUSION

RLPS is a rare malignant neoplasm generally difficult to detect early due to its late and nonspecific clinical presentation. CECT represents the most commonly used modality for diagnosis, staging and preoperative evaluation. Surgery represents the appropriate treatment of non-metastatic RLPS.

Deep Learning Networks for Automatic Retroperitoneal Sarcoma Segmentation in Computerized Tomography

The volume estimation of retroperitoneal sarcoma (RPS) is often difficult due to its huge dimensions and irregular shape; thus, it often requires manual segmentation, which is time-consuming and operator-dependent. This study aimed to evaluate two fully automated deep learning networks (ENet and ERFNet) for RPS segmentation. This retrospective study included 20 patients with RPS who received an abdominal computed tomography (CT) examination. Forty-nine CT examinations, with a total of 72 lesions, were included. Manual segmentation was performed by two radiologists in consensus, and automatic segmentation was performed using ENet and ERFNet. Significant differences between manual and automatic segmentation were tested using the analysis of variance (ANOVA). A set of performance indicators for the shape comparison (namely sensitivity), positive predictive value (PPV), dice similarity coefficient (DSC), volume overlap error (VOE), and volumetric differences (VD) were calculated. There were no significant differences found between the RPS volumes obtained using manual segmentation and ENet (p-value = 0.935), manual segmentation and ERFNet (p-value = 0.544), or ENet and ERFNet (p-value = 0.119). The sensitivity, PPV, DSC, VOE, and VD for ENet and ERFNet were 91.54% and 72.21%, 89.85% and 87.00%, 90.52% and 74.85%, 16.87% and 36.85%, and 2.11% and -14.80%, respectively. By using a dedicated GPU, ENet took around 15 s for segmentation versus 13 s for ERFNet. In the case of CPU, ENet took around 2 min versus 1 min for ERFNet. The manual approach required approximately one hour per segmentation. In conclusion, fully automatic deep learning networks are reliable methods for RPS volume assessment. ENet performs better than ERFNet for automatic segmentation, though it requires more time.

OUP accepted manuscript

Retroperitoneal lipoma is exceedingly rare, and due to the difficulty in distinguishing between retroperitoneal lipoma and well-differentiated liposarcoma (WDLS), recommendation is en-bloc resection. A 58-year-old male was investigated for scrotal swelling, ultrasound and computed tomography showed a well-defined lipomatous mass occupying much of the left side of the lower abdomen. At laparotomy, a large left-sided retroperitoneal mass was found. Histology reported a 160 mm × 150 mm × 90 mm fatty tumour weighing 1540 g. MDM2 gene amplification was not present on fluorescence in situ hybridization. No significant somatic signatures were identified on whole exome sequencing. Retroperitoneal fatty tumours represent a diagnostic dilemma. Sampling via core biopsy has been recorded at 85% accuracy for WDLS. Positive amplification of the MDM2 gene supports a diagnosis of WDLS; however, a negative biopsy does not exclude the diagnosis due to varied amplification among different cells in the same tumour.

Analysis of potential risk factors in the survival of patients with primary retroperitoneal liposarcoma

INTRODUCTION

The present work is an observational study of a series of variables regarding overall survival and disease-free survival in patients diagnosed with primary liposarcoma.

METHODS

The study is prospective with retrolective data collection that includes all patients with primary liposarcoma referred to Hospital Son Espases University Hospital, Palma de Mallorca, Spain from January 1990 to December 2019.

RESULTS

The study includes 50 patients and the compartment surgery was performed in 18 patients (36%) of cases. The mean overall survival of the sample was 15.57 years (95% CI: 12.02-19.12) and the mean disease-free survival was 6.70 years (95% CI: 4.50-8.86).

CONCLUSION

Compartment surgery has not shown benefits in terms of overall survival and disease-free survival. The ASA classification (≥3) predicts a poor prognosis in both overall survival and disease-free survival. Resection with free margins, described on the pathological results and defined in this work as R0, show better disease-free survival.

Single-Center Experience of Surgical Treatment of Primary Retroperitoneal Tumors

This study is an evaluation of surgical treatment results of primary retroperitoneal tumors. In Samara Regional Clinical Oncology Dispensary, from 2008 to 2015, the treatment of 187 patients (53 men and 134 women) was conducted. One hundred fifteen patients got tumor removal within the healthy tissue (R0), and 61 patients went through complete resection of tumor with wide margins (R0). Complete resection of tumor with wide margins (R0) with preoperative tumor vessel embolization was performed in 11 patients. According to the histological examination, malignant retroperitoneal tumor was detected in 85 patients (48.4%); in most cases it was presented by various forms of sarcoma. A benign tumor was diagnosed in 71 patients (40.3%), fibrolipomas (17.1%), and neurofibromas (12.5%). The diagnosis of 20 patients needs subsequent clarification, as mesenchymal tumor (6.2%) and histiocytoma (5.1%) were diagnosed. Short-term results of surgical treatment for the group, where complete resection of tumor with wide margins was performed: intraoperative blood loss 410.91 + - 113.31(ml), operation time 185.15 + -32.49(min); postoperative complications 10 (16,4%); mortality 3 (4,9%); LOS 23,14 ± 6,31; for removal of the tumor within healthy tissues: intraoperative blood loss 281.33 + -110.94 (ml), operation time 58.33 + -27.14(min) postoperative complications 7 (6,08%); mortality 2 (1,74%); LOS 6,98 ± 4,83; (t = 279, p = 0,015). For patients who went through preoperative tumor feeding vessel embolization, intraoperative blood loss was 121.33 ± 27.94 (ml), time of operation 43.13 ± 16.11 (min), postoperative complication 1 (4.5%), mortality 0 (0%), and length of stay 12.72 ± 1.49. After the complete resection of tumor with wide margins, intraoperative blood loss, operation time, the number of postoperative complications, and postoperative LOS were significantly greater in comparison with the group of patients where the tumor was removed within healthy tissues. The method of preoperative embolization of the tumor feeding vessels can reduce intraoperative blood loss, the time of operation, and the number of postoperative complications.

Clinical and Pathological Characteristics of Soft Tissue Sarcomas: A Retrospective Study From a Developing Country

Introduction Soft tissue sarcomas remain an exceedingly rare malignancy. While soft tissue sarcomas boast a high mortality rate, their characteristics and behavior patterns are poorly understood. This study aims to evaluate the various aspects that pertain to soft tissue sarcomas, including their histology, tumor characteristics, survival rates, and therapeutic modalities. Methods A retrospective study analyzing the data from 19 patients presenting over four years with a histologically confirmed diagnosis of soft tissue sarcomas was conducted. The patients were studied for various parameters, including tumor site and the particular pathological subtypes. The data obtained were analyzed using the SPSS 23.0 statistical software (IBM Corporation, Armonk, NY), and the results were then tabulated. Results A total of 19 patients with a confirmed diagnosis of a soft tissue sarcoma were included in the study. The mean age of the patients included was 45.32 ± 16.88 years. Wide local excision was the most common surgical procedure employed for the resection of these tumors. Within the cohort, the mortality rate was noted to hover at 10.52%. Gastrointestinal stromal tumors were observed in 21% of the patients and were therefore the most common histological subtype. Of the patients included, 42.10% required blood transfusion during the perioperative time. Most of the tumors were noted to be intermediate grade, with high-grade tumors observed in 26.3% of the cases. Conclusion Soft tissue sarcomas remain a rare but potent cause of death in developing countries. The diversity of the tissues that they afflict renders their prompt detection a diagnostic challenge. A meticulous exploration of the various characteristics honed by soft tissue sarcomas, such as the particular histological subtype and the associated mortality rates, can better elucidate the prognosis and the eventual disease outcomes.

Retroperitoneal Sarcomas: Prognostic Factors and Outcomes of a Series of Patients Treated at a Single Institution

Retroperitoneal sarcomas (RPS) are rare heterogeneous tumors arising in the retroperitoneum with unique biological and behavioral patterns that are thought to be closely linked to histology. The aim of the study was to audit our results and analyze various clinico-pathological factors including surgical excision, histology, and their implications on the recurrences and survival outcomes in RPS. Retrospective analysis of patients treated at a tertiary referral center in India from March 2008 to July 2017 was performed. The clinico-pathological variables were analyzed for their association with tumor recurrence and survival with special emphasis on histological subtype. The primary outcome was overall survival (OS). One hundred consecutive patients operated for RPS were analyzed. Of these, 27 were operated for recurrent tumors. Liposarcomas (LPS) and leiomyosarcomas (LMS) constituted 50% (n = 50) and 30% (n = 30) of patients respectively. Complete tumor excision was achieved in 83%, with 43% patients undergoing adjacent organ resection. At a median follow-up of 25.3 months, the median disease-free survival (DFS) and overall survival (OS) were 30 months and 87.8 months respectively. On multivariate analysis, tumor grade was the only factor to significantly affect survival (p = 0.001 for DFS and 0.005 for OS). There was no difference in survival outcomes between infiltrative and adhesive tumors with respect to adjacent organ invasion (p = 0.361 for OS). Tumor grade remains an important prognostic factor affecting disease-free and overall survival in retroperitoneal sarcomas irrespective of tumor size, site, and histology.

Primary retroperitoneal liposarcoma with extensive ossification: A case report

RATIONALE

Primary retroperitoneal liposarcoma, which originates from mesenchymal tissues, can rarely present with extensive ossification.

PATIENT CONCERNS

A 41-year-old male patient presented with a chief complaint of discomfort around the waist for 2 months.

DIAGNOSES

Computerized tomography (CT) and magnetic resonance imaging suggested a lesion of approximately 5.6 × 5.1 × 8.7 cm in front of the psoas major muscle, which was considered to be a mesenchymal or neurogenic tumor.

INTERVENTIONS

The hard mass was removed by laparotomy, and the pathological investigation revealed that this was an atypical lipomatous tumor/well-differentiated liposarcoma, with extensive ossification.

OUTCOMES

The patient was discharged from the hospital after surgery. There was no sign of reoccurrence after 1 year of follow-up.

LESSONS

Retroperitoneal liposarcomas with extensive ossification are rare tumors that can present with nonspecific symptoms, and are difficult to diagnose. CT is the most common imaging technique, and surgical resection has been considered to be the most effective treatment. This rare case can be challenging for diagnosis and treatment.

Practical approach to primary retroperitoneal masses in adults

Primary retroperitoneal masses constitute a heterogeneous group of uncommon lesions and represent a challenge due to overlapping imaging findings. Most are malignant lesions. Although they are more prevalent in adults, they can occur at any age. Such lesions are classified as primary when they do not originate from a specific retroperitoneal organ and are divided, according to the image findings, into two major groups: solid and cystic. The clinical findings are nonspecific and vary depending on the location of the lesion in relation to adjacent structures, as well as on its behavior. The main imaging methods used for staging and surgical planning, as well as for selecting the biopsy site and guiding the biopsy procedure, are computed tomography and magnetic resonance imaging. In most cases, the treatment is challenging, because of the size of the lesions, vascular involvement, or involvement of adjacent organs. In this article, we present a review of the retroperitoneal anatomy and a practical approach to the main imaging features to be evaluated, with a view to the differential diagnosis, which can guide the clinical management.

Neuropraxia following resection of a retroperitoneal liposarcoma

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Neuropraxia after resection of retroperitoneal masses can be a challenging postoperative problem.

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Intraoperative findings and postoperative suspicion have utmost importance in establishing differential diagnosis.

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Postoperative work up including neurological evaluation, MRI, and EMG help in diagnosing the condition.

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Aggressive postoperative physical therapy and steroids are very helpful in resolution of the condition.

Background

This is a unique case of neuropraxia of femoral nerve seen after resection of retroperitoneal liposarcoma which has not been reported before in the literature.

Introduction

Neuropraxia, a transient paralysis due to blockage of nerve conduction, commonly associated with athletes and orthopedic procedures, has not been previously reported as a complication following resection of retroperitoneal sarcoma.

Case

This is an 81-year-old female who, on CT for evaluation of her atherosclerosis, was found to have an incidental right-sided retroperitoneal mass extending from the right renal capsule inferiorly through the inguinal canal. At this point, the patient reported mild right sided abdominal pain and right lower back pain, but reported no neuromotor deficits of the right lower extremity. Given the symptoms of the patient as well as the size, location and the density of the lesion, surgical intervention was pursued. On exploration, the lipomatous lesion, suggestive of liposarcoma, was invading the right genitofemoral nerve and ilioinguinal nerve which were sacrificed to ensure a complete oncologic resection. Following complete removal of the mass, she developed right side femoral nerve neuropraxia, suffering complete loss of motor function in the femoral distribution. Pathology revealed the mass to be a low grade liposarcoma.

Discussion

The patient required only physical therapy and oral prednisone following surgery for treatment of the neuropraxia. She responded well and has regained significant neuromotor function of the affected limb. Cases presenting with post-resection neurological sequelae without any known intraoperative nerve injury may respond very well to conservative treatment. Hence, it is very important to collaborate with Neurology and Physical Therapy to achieve best possible outcome.

Effect of intraoperative radiotherapy in the treatment of retroperitoneal sarcoma

BACKGROUND

Current National Comprehensive Cancer Network guidelines for the treatment of retroperitoneal sarcomas (RPS) endorse surgical resection, but the role of radiotherapy (RT) is less clear. We investigate the utilization and benefits of intraoperative RT (IORT) in the treatment of RPS.

METHODS

We queried the Surveillance, Epidemiology and End Results (SEER) database (1988-2013) for the utilization of IORT and perioperative external beam RT (EBRT) in patients who underwent surgical resection of RPS. Groups were defined as any IORT (aIORT), IORT alone (IORT-), IORT with EBRT (IORT+) and preoperative and/or postoperative EBRT without IORT (EBRT). Demographics, tumor characteristics, extent of disease, and survival were compared between groups.

RESULTS

We identified 908 patients with RPS who underwent surgical resection with perioperative RT. Demographics of age, sex, and race were similar between groups. There was no difference in baseline tumor characteristics of mean size, tumor grade, or histological subtype between groups. A higher percentage of patients receiving aIORT had tumors >20 cm in size, and extension beyond local tissues. Liposarcoma and leiomyosarcoma were the most common subtypes overall and in each subgroup. Patients with liposarcoma undergoing IORT and EBRT (IORT+) demonstrated a survival benefit over both IORT alone (IORT-) and EBRT alone.

CONCLUSION

IORT was used infrequently for RPS but generated equivalent outcomes compared to EBRT, despite being utilized more often for larger tumors and those with peri-tumoral soft-tissue invasion. Patients with the most common subtype (liposarcoma) may benefit from combination IORT with adjuvant EBRT versus other regimens.

Radiological diagnosis of perinephric pathology: pictorial essay 2015

The perinephric space, shaped as an inverted cone, sits between the anterior and posterior renal fasciae. It can play host to a variety of clinical conditions encountered daily in the reporting schedule for a radiologist. Lesions may be classified and diagnosed based on their imaging characteristics, location and distribution. A broad range of differential diagnoses can be attributed to pathology sitting within this space, often without clinical signs or symptoms. An understanding of commonly encountered conditions affecting the perinephric space, along with characteristic imaging findings, can illustrate and often narrow the likely diagnosis. The aim of this essay is to describe commonly encountered neoplastic and non-neoplastic entities involving the perinephric space and to describe their key imaging characteristics.

TEACHING POINT

• Despite often a bulky disease, perinephric lymphoma does not produce obstruction or stenosis. • In primarily fatty masses, defects within the renal capsule likely represent angiomyolipoma. • Consider paraganglioma if biopsy is planned; biopsy may lead to catecholamine crisis.

The gamut of primary retroperitoneal masses: multimodality evaluation with pathologic correlation

The retroperitoneum is a large space where primary and metastatic tumors grow silently before clinical signs appear. Neoplastic retroperitoneal diseases may be solid or cystic, primary or secondary and range from benign to aggressive in behavior. Retroperitoneal neoplasms are notable for their widely disparate histologies. The solid primary retroperitoneal neoplasms are extremely uncommon and can be classified based on their tissue of origin into three main categories: mesodermal tumors, neurogenic tumors, and extragonadal germ cell tumors. These tumors can grow to a large size before clinical symptoms occur or become palpable. When symptoms do occur, they are nonspecific. The majority of these masses are malignant and imaging plays a pivotal role in the detection, staging, and pre-operative planning. Benign and malignant masses should be distinguished whenever possible to avoid unnecessary surgical procedures. Macroscopic fat, calcification, necrosis, vascularity, and neural foraminal widening are common imaging features helping for tumor differentiation. Meticulous cross-sectional imaging can triage the patient to the most appropriate therapy. Tumor morphology dictates imaging character, and biologic activity is reflected by positron emission tomography (PET). Complete surgical excision with tumor free margins is essential for long-term survival. Biopsy should be performed in consultation with surgical oncology to avoid complicating curative surgery. This pictorial essay illustrates the spectrum of multidetector computed tomography (MDCT) imaging findings in common and uncommon primary retroperitoneal masses, with an emphasis on cross-sectional imaging features for an adequate tumor characterization and staging.

Primary retroperitoneal masses: what is the differential diagnosis?

Primary retroperitoneal masses include a diverse, and often rare, group of neoplastic and non-neoplastic entities that arise within the retroperitoneum but do not originate from any retroperitoneal organ. Their overlapping appearances on cross-sectional imaging may pose a diagnostic challenge to the radiologist; familiarity with characteristic imaging features, together with relevant clinical information, helps to narrow the differential diagnosis. In this article, a systematic approach to identifying and classifying primary retroperitoneal masses is described. The normal anatomy of the retroperitoneum is reviewed with an emphasis on fascial planes, retroperitoneal compartments, and their contents using cross-sectional imaging. Specific radiologic signs to accurately identify an intra-abdominal mass as primary retroperitoneal are presented, first by confirming the location as retroperitoneal and secondly by excluding an organ of origin. A differential diagnosis based on a predominantly solid or cystic appearance, including neoplastic and non-neoplastic entities, is elaborated. Finally, key diagnostic clues based on characteristic imaging findings are described, which help to narrow the differential diagnosis. This article provides a comprehensive overview of the cross-sectional imaging features of primary retroperitoneal masses, including normal retroperitoneal anatomy, radiologic signs of retroperitoneal masses and the differential diagnosis of solid and cystic, neoplastic and non-neoplastic retroperitoneal masses, with a view to assist the radiologist in narrowing the differential diagnosis.

Multidetector Computed Tomography Features in Differentiating Exophytic Renal Angiomyolipoma from Retroperitoneal Liposarcoma: A Strobe-Compliant Observational Study

This study aims to evaluate the multidetector computed tomography (CT) imaging features in differentiating exophytic renal angiomyolipoma (AML) from retroperitoneal liposarcoma. We retrospectively enrolled 42 patients with confirmed exophytic renal AML (31 patients) or retroperitoneal liposarcoma (11 patients) during 8 years period to assess: renal parenchymal defect at site of tumor contact, supply from branches of renal artery, tumoral vessel extending through the renal parenchyma, dilated intratumoral vessels, hemorrhage, non-fat-containing intratumoral nodules with postcontrast enhancement, calcification, renal sinus enlargement, anterior displacement of kidneys, and other associated AML. Renal parenchymal defect, renal arterial blood supply, tumoral vessel through the renal parenchyma, dilated intratumoral vessels, intratumoral/perirenal hemorrhage, renal sinus enlargement, and associated AML were seen only or mainly in exophytic renal AML (all P value < 0.05); however, non-fat-attenuating enhancing intratumoral nodules, intratumoral calcification, and anterior displacement of the kidney were more common in liposarcoma (all P value < 0.05). AMLs reveal renal parenchymal defect at the site of tumor contact, supply from renal artery, tumoral vessel extending through the renal parenchyma, dilated intratumoral vessels, intratumoral and/or perirenal hemorrhage, renal sinus enlargement, and associated AML. Non-fat-attenuating enhancing intratumoral nodules, intratumoral calcifications, and anterior displacement of kidney were more commonly seen in liposarcoma.

A comprehensive review of the retroperitoneal anatomy, neoplasms, and pattern of disease spread

A clear understanding of the normal anatomy and pattern of disease spread is important in evaluating many retroperitoneal disorders. Primary retroperitoneal tumors are uncommon, accounting for 0.1%-0.2% of all malignancies in the body; 80%-90% of all primary retroperitoneal tumors are malignant. The primary retroperitoneal neoplasms can be divided into solid or cystic masses. The solid neoplasms can be classified according to their tissue of origin into 3 main categories: mesodermal tumors, neurogenic tumors, and extragonadal germ cell tumors. Computed tomography and magnetic resonance imaging play a vital role in the localization, characterization, evaluation of the extent of local invasion, assessment of metastases, and determination of treatment response for these tumors. The diagnosis of a primary retroperitoneal malignancy is often challenging owing to overlap of imaging findings. A definitive diagnosis can be established only at histopathologic analysis. However, knowledge of the important tumor characteristics, growth pattern, and vascularity can assist in narrowing the differential diagnosis.

Therapeutic experience with primary liposarcoma from the sigmoid mesocolon accompanied with well-differentiated liposarcomas in the pelvis

Multifocal liposarcoma with different histological types is rare, especially that originating from the mesentery. We herein report a case of primary myxoid liposarcoma from the sigmoid mesocolon that was accompanied with well-differentiated liposarcomas in the pelvis. The location, the fat signal and the relationship with adjacent organs of the liposarcomas were well shown in the axial, coronal and sagittal dimensions of MRI, giving a comprehensive and specific image before surgery. To alleviate the patient's symptoms and mental stress, a laparotomy was performed. The tumors were all completely excised with macroscopic free margins. The final histopathological report showed that the tumor in the sigmoid mesocolon was a pure myxoid liposarcoma, while the pelvic tumors were spindle cell liposarcomas, a special type of well-differentiated liposarcoma. According to the AJCC staging system, they were all stage IIB. No further adjuvant therapy was performed. Close follow-up after the surgery has been performed, and the patient has remained healthy without any evidence of recurrence or metastasis for 17 months after the surgery.

[Operative therapy of abdominal and retroperitoneal sarcoma]

Retroperitoneal soft tissue sarcomas are characterized by a high rate of local recurrence. Complete tumor resection is the only potentially curative therapeutic option. The concept of a systematic compartmental resection is to remove the tumor en bloc with a margin of uninvolved tissue and organs. This is frequently only achieved by multivisceral resection which often includes kidney, colon, pancreas and parts of the diaphragm or the psoas muscle. The adoption of such a policy of multivisceral organ resection improves the proportion of curative resections and, ultimately, results in lower local recurrence rates. The present article comprehensively describes the operative procedures, perioperative treatment and the oncological results of surgery for retroperitoneal sarcomas. The role of surgery in oncological treatment plans and the importance of specialized centres are outlined in detail.

A retrospective study comparing contrast-enhanced computed tomography with 18F-FDG-PET/CT in the early follow-up of patients with retroperitoneal sarcomas

OBJECTIVE

To compare 18-fluorine-labeled 2-deoxy-2-fluoro-D-glucose PET/computed tomography ((18)F-FDG-PET/CT) with contrast enhancement computed tomography (CECT) in the early follow-up of patients who had undergone treatment for primitive retroperitoneal sarcomas (RS).

METHODS

This is a retrospective study on 24 patients who underwent (18)F-FDG-PET/CT and CECT within 2 years after therapy for RS. (18)F-FDG-PET/CT and CECT results were compared with results of histological examination and clinical-instrumental follow-up. We calculated the sensitivity and specificity of CECT and (18)F-FDG-PET/CT for retroperitoneal recurrences and compared them with results of the McNemar test. Negative predictive values (NPVs) and positive predictive values (PPVs) were calculated and the positive percentage agreement and negative percentage agreement were evaluated.

RESULTS

The sensitivity and specificity of (18)F-FDG-PET/CT were 66.7 and 100% and those for CECT were 58.3 and 50%, respectively. For (18)F-FDG-PET/CT, PPV was 100% [95% confidence interval (CI): 67-100%] and NPV was 75% (95% CI: 58-75%); for CECT, PPV was 54% (95% CI: 33-73%) and NPV was 55% (95% CI: 30-78%). Positive percentage agreement and negative percentage agreement were, respectively, 38 and 72% for retroperitoneal lesions, 42.8 and 100% for liposarcomas, 40 and 50% for leiomyosarcomas, 14.2 and 94% for abdominal lymph nodes, and 16.6 and 100% for lung metastasis. Neither technique gave reliable results for liver metastasis.

CONCLUSION

Our data show that (18)F-FDG-PET/CT has a higher overall specificity compared with CECT in identifying areas of recurrence, demonstrating its validity for early whole-body detection of lesions. In our hands (18)F-FDG-PET/CT seems to be a good tool in the early follow-up of patients experiencing recurrence of RS.

Retroperitoneal sarcomas- a challenging problem

Retroperitoneal sarcomas are relatively rare tumours and usually present in a locally advanced stage. Liposarcoma is the most common histopathology. If operable, surgery is the treatment of choice. The role of adjuvant chemotherapy or radiotherapy is not yet defined. Advanced cases are treated by chemotherapy. The prognosis is poor in patients with positive resection margins, high-grade tumours and recurrent tumours.

Luteinizing hormone, sex steroids and extracorporeal circulation - a promising link to treat retroperitoneal sarcomas. A reconsideration of cancer treatment

Retroperitoneal sarcomas are rare and aggressive tumors with a negative prognosis as there is currently no satisfactory treatment for them. The only proven factor that can significantly increase the otherwise poor survival of sarcoma patients is the radically of resection. However, the completeness of resection is hindered by the hypervascularized nature of sarcomas and the frequent involvement of major blood vessels. In this context, we propose to operate on retroperitoneal sarcomas only with the use of extracorporeal circulation, applying vascular clamps above and below the tumor, even with short periods of hypothermic circulatory arrest in complex cases. This technique would allow the surgeon to achieve complete tumor resections, approach large blood vessels easier and perform sofisticated vascular reconstructions with no fear of hemorrhage which is fundamental to achieve a bloodless surgical field. Also, we speculate on the etiology of retroperitoneal sarcomas that appear mostly during the period of menopause/andropause. Although both estrogens and androgens have been incriminated in inducing various cancer types, including sarcomas, an endogenous estradiol cathabolyte has been shown to have anti-tumor effects. Considering that during menopause/andropause sex steroid levels actually decrease, our second working hypothesis is that the increasing follicle-stimulating hormone (FSH) and especially luteinizing hormone (LH) levels, together with the relative estrogen/androgen imbalance, may be the triggering cause. Also, a certain level of estrogens (Methoxyestradiol) may be essential in limiting tumor development and dedifferentiation. Given that extragonadal sarcomas appear to behave as endocrine tumors, a targeted hormonal therapy, together with controlled radical resections in complex cases of tumor vascular involvement, would certainly provide a strong link to both prevention and treatment of retroperitoneal sarcomas and even of cancer in general.

Pelvic Leiomyosarcoma obstructing vaginal opening — case report

We present a 42-year-old female admitted for a 4 month history of increasing pelvic discomfort and pain. Clinical examination revealed a large tumor obstructing the vagina. Tumor markers (CA 125, CEA, AFP and CA 19-9), white blood cells and biochemical tests were all within the normal limits. Pelvic ultrasound and magnetic resonance imaging scan confirmed the presence of a large retroperitoneal/pelvic mass. The tumor was surgically excised and pathohistologically diagnosed as a well differentiated leiomyosarcoma, staged IB. Six years after surgery the patient is well and disease free.

Primary retroperitoneal synovial sarcoma in CT and MRI

Synovial sarcomas are most commonly localized in the extermities, especially the lower thigh and knee areas. Retroperitoneal synovial sarcoma is very rare. We decribe the radiological findings of an adult retroperitoneal synovial sarcoma.

[Retroperitoneal neoformation: case study]

Retroperitoneal sarcoma represents approximately 12-15% of all sarcomas and between 0.2 and 0.5% of all neoplasia. They very rarely metastasize, and the main cause of death is local recurrence. Radiotherapy and chemotherapy still do not represent valid therapeutic alternatives, therefore radical surgery remains the only valid option. We would like to present the following case of a 48-year-old male patient. After episodes of right-side renal colic, a 19x16x19 cm mass was found, which was palpable in the right quadrants, englobed the right ureter and caused ipsilateral hydroureteronephrosis of medium grade. Surgery allowed total excision of this neoplasm (which was tenaciously attached to various organs), with the sacrifice of the right kidney. The final histological examination on a sample taken during surgery confirmed that the neoplasm was a spindle-cell sarcoma at an intermediate grade of malignancy. One year after surgery the patient is disease free.

Giant Retroperitoneal Liposarcoma Mimicking Ovarian tumour - A Case report

Retroperitoneal liposarcomas are rare tumours representing less than 1% of all malignant tumours. They are generally slow growing and may attain enormous sizes. We report a case of a giant (9.8kg) retroperitoneal liposarcoma in a 65 years old lady which was initially misdiagnosed as an ovarian tumour. She had a successful surgical removal and has been followed up for more than one year with no evidence of recurrence.

CT characteristics of primary retroperitoneal neoplasms in children

Primary retroperitoneal neoplasms are uncommon in children. Retroperitoneal neoplasms are either mesodermal, neurogenic, germ cell ectodermal or lymphatic in origin. In general, primary retroperitoneal neoplasms in children have different spectrum and prevalence compared to those in adults. Neuroblastoma, rhabdomyosarcoma, benign teratoma and lymphoma are the common retroperitoneal neoplasms. In this review, the clinical and CT futures of common retroperitoneal neoplasms in children are described. Coarse, amorphous, and mottled calcification are very common in neuroblastoma. Paraganglioma tends to show marked and early enhancement and may present with clinical symptoms associated with the excess catecholamine. Sarcomas are often very large and have heterogeneous appearance. Imaging cannot be reliably used to identify the type of retroperitoneal sarcomas due to overlapped radiographic features. In children, lipoblastoma is the most common lipomatous tumor in the retroperitoneum. The percentage of visible fat in tumor varies depending on the cellular composition of the lesion. The CT characteristics of teratoma are quite variable, which may be cystic, solid, on a combination of both. Typically teratoma appears as a large complex mass containing fluid, fat, fat-fluid level, and calcifications. Lymphoma is often homogeneous on both enhanced and unenhanced CT scans. Necrosis and calcification are rare on CT. In conclusion, making a final histological diagnosis of retroperitoneal tumor base on CT features is not often possible; however, CT can help to develop a differential diagnosis and determine the size and extent of the retroperitoneal neoplasms.

A large retroperitoneal tumor with psoas infiltration: A rare case report

CONTEXT

Retroperitoneal sarcomas are rare neoplasms. Computed Tomography or Magnetic Resonance Imaging is performed in patients with these tumors to detect local extent and distant metastases of the tumor and for preoperative surgical planning. However the evaluation and treatment of retroperitoneal sarcomas are challenging because of its rarity and frequent presentation with advanced disease in an anatomically complex location.

CASE REPORT

We report a case of large retroperitoneal tumor in a female on the right flank. Ultrasound and Computed tomography scan of the abdomen revealed infiltration into the psoas muscle on the same side along with displacement of adjacent structures. Ultrasound guided fine needle aspiration cytology was suggested of liposarcoma. Surgical resection of the tumor was done. In follow up six months, patient was asymptomatic.

CONCLUSIONS

In case of retroperitoneal tumors CT scan remains the diagnostic modality of choice and the inefficiency of adjuvant therapy; high recurrence rate and the very low chance of curing the patient after recurrence make the prognosis of these patients poor. However surgical resection remains the optimum treatment in all cases of retroperitoneal tumors.

Histology and imaging of soft tissue sarcomas

Imaging and histology are two complementary morphological techniques which play a fundamental role in the diagnosis and management of soft tissue sarcomas. Imaging allows to identify some pseudosarcomatous benign lesions such as myositis ossificans, intramuscular hemangioma, angiomyolipoma, intramuscular lipoma, giant cell tumour of tendon sheath, desmoid tumour and elastofibroma. There is no formal criterion for diagnosing a sarcoma on magnetic resonance imaging (MRI) but malignancy is strongly suspected with the presence of necrosis and vascular, bone or joint invasion. Imaging may also suggest some histological types of sarcoma such as well-differentiated liposarcoma, dedifferentiated liposarcoma, synovial sarcoma or extraskeletal osteosarcoma. Imaging is also extremely helpful in determining the appropriate kind of sampling to carry out and in guiding the performance of a microbiopsy. The appearance observed on imaging should always be taken into consideration for the interpretation of the microbiopsy by the pathologist.